Active Link Cable Mesh

ABSTRACT

An active link wireless cable mesh network and a method for transmitting data in a wireless cable mesh network are provided. A plurality of end devices are connected in a mesh configuration. A data message is transmitted to a first end device via one of a plurality of antennas radiating elements which form a phased array antenna. If the message is not successfully received, the antenna radiating elements is steered to another transceiver in the mesh network to complete the transmission.

FIELD OF THE INVENTION

This disclosure relates generally to cable mesh networks, and moreparticularly to the use of a phased array antenna in a cable meshnetwork.

BACKGROUND OF THE INVENTION

Data-over-cable communication systems are frequently used to connectpersonal computers to the Internet and other networks. Data-over-cablecommunication systems allow high speed data distribution over cabletelevision networks. However, the cost associated with installing theequipment necessary to provide data-over-cable access in a widespreadmanner can be quite high.

Currently, wireless connections have been used to provide cable accessto areas not previously reached with hard wired data-over-cable accessequipment. By utilizing wireless networks to provide cable access to newcustomers, it is possible to eliminate the high cost associated withproviding hard-wire connections to the new customers. As one example,wireless mesh networks are utilized, which comprise wireless antennasplaced at cable access points. The cable access point comprisescomponents which allow customers to access (i.e., the reception andtransmission of data) the cable system via a wireless connection. Thewireless antennas disposed at the cable access points transmit andreceive data to and from a particular area, referred to as a segment.Typically, omni-directional antennas are used at the cable accesspoints. As is known, omni-directional antennas transmit and receivesignals to and from all directions.

However, while omni-directional antennas are inexpensive and widelyused, they have many drawbacks. For example, as a result of their broadtransmission patterns, omni-directional antennas are susceptible tointentional jamming and interference. As such, there is a need for awireless cable mesh network having components that are able to eliminatethe problems associated with utilizing omni-directional antennas incable access points in wireless cable-over-data systems, such as, reducethe effects of jamming and interference.

SUMMARY OF THE INVENTION

Accordingly, the present invention relates to a wireless cable-over-datasystem and method for implementing such a system, which overcomes theforegoing problems. More specifically, the present invention provides acable access point having a programmable antenna, which allows foractive control of the direction of transmission and reception of signalsby the antennas. In other words, the present invention allows for activecontrol of the antenna pattern associated with a given antenna at agiven cable access point. As a result of the present invention, it ispossible, for example, to electronically steer the reception pattern ofthe antenna so as to avoid a signal being transmitted as an interfereror jammer in a wireless mesh network.

In accordance with one embodiment of the present invention, a wirelesscable network comprises a plurality of transceivers located at a cableaccess point and configured to transmit and receive data over a cablenetwork to and from a plurality of transceivers located at an end userdevice. At least two of the plurality of transceivers located at the enduser device are communicatively coupled to each other in a meshconfiguration, wherein, at least one of the plurality of transceiverslocated at the cable access point is equipped with an electronicallysteerable phased array antenna capable of transmitting a steerable bean,and for controlling the received signal pattern associated with theantenna. The mesh configuration enables a signal to be routed betweenthe plurality of end user devices.

The phased array antenna includes a controller configured to performbeam steering and null steering. That is, the controller is configuredto direct the radiating antenna elements forming the phased arrayantenna to direct their transmissions to particular destinations. If alink between an antenna element and its destination becomes blocked, thecontroller directs the radiating element to steer its signal to anotherreceiver in the mesh in order to complete the transmission.Additionally, the controller may be configured to null out any jammerswithin the transmission area.

According to another embodiment, one or more end devices, such as auser's home, may be equipped with a phased array antenna. Because theend devices are connected in a mesh configuration, a device equippedwith a phased array antenna can cause its antenna to transmit andreceive data through another end device in the event of signal blockage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a conventional cable mesh network.

FIG. 2 depicts a cable mesh network incorporating a phased arrayantenna.

FIG. 3 depicts a phased array antenna incorporated into a transmittinglocation.

FIG. 4 depicts a method of transmitting data in a mesh network, inaccordance with one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 depicts a conventional cable mesh network 100. Cable mesh network100 comprises a multiple subscription operator (MSO) 110 connected tonetwork 130. Network 100 further comprises a plurality of firsttransceivers 120 (each of which is capable of transmitting and receivingsignals) located at a plurality of cable access points andcommunicatively coupled to MSO 110 and to a plurality of secondtransceivers 140 (each of which is capable of transmitting and receivingsignals) associated with a plurality of end user devices. MSO 110 may beany cable service provider which enables the exchange of data betweenthe end user devices and network 130. The mesh configuration enableseach second transceiver 140 located at the end user device tointerconnect with one or more other second transceivers 140 in additionto first transceivers 120. Signals may be routed through the meshnetwork from device to device until reaching the correct destination.

In accordance with traditional cable communications technology, eachfirst transceiver 120 is equipped with an omni-directional antenna 122,configured to transmit and receive signals from all directions within adefined area. Specifically, omni-directional antenna 122 is configuredto transmit and receive signals to and from second transceivers 140located at each end user device. As depicted in FIG. 1, omni-directionalantenna 122 transmits and receives signals through wirelesscommunication links 142. Furthermore, in accordance with meshtechnology, second transceivers 140 may be connected to each otherthrough wireless links 154. Accordingly, each second transceiver 140located at an end user device may communicate with other antennas atother end devices. Thus, in the event a link is unavailable, each devicecan still transmit and receive data to and from network 130.Additionally, one or more of the first transceivers 120 may becommunicatively coupled to another of the transceivers via a wirelesstransmission link (not illustrated).

FIG. 2 depicts an exemplary cable mesh network 200, in accordance withone embodiment of the present invention. Cable mesh network 200 differsfrom network 100 in that omni-directional antenna 122 is replaced with aphased array antenna 222. Phased array antennas located at a cableaccess point may be configured to communicate with one or more of theplurality transceivers associated with each end user devices.Additionally, phased array antennas located at the cable access pointmay communicate with other access point transceivers in the network. Theuse of phased array antennas enhances communications within the networkby providing electronically steerable beams. The phased array antennamay be configured by a controller to perform techniques such as, forexample, beam steering, null steering, and switching (i.e. switchingfrom one antenna or transceiver to another). These techniques enhancecommunication for example, by enabling the controller to actively steeraround obstructions and interferers in the network.

There are many methods for phased array antenna control including, butnot limited to, phase shifting radiating elements or groups of elements,attenuating or amplifying signals of individual radiating elements orgroups of radiating elements, adjusting the frequency of signals(thereby adjusting the elements' spacing in terms of wavelength), andsliding mechanical devices. Phased array antennas can provide high gaindirectional antenna patterns that are desirable when in the presence ofground reflections and noise sources. Additionally, phased arrayantennas may be used to provide multiple beams and channels forsimultaneous links to multiple locations. Phased array antennas, whichhave adjustable gain and pattern shape, may be used to suppressundesired signals from multiple locations (nulling). Additionally,phased array antennas may be electronically controlled and switched,enabling the antennas to operate in time division modes. According toone embodiment, the use of phased array antennas in a cable mesh networkenables the network to allocate and parse links in defined time frames.The phased array antenna may provide terrestrial to terrestrial links,or any form of terrestrial to air/space links.

FIG. 3 depicts a phased array antenna 300, which may be installed at acable access point, in accordance with one configuration. Phased arrayantenna 300 comprises a radio frequency (RF) splitting network 310, aplurality of attenuators 320, a plurality of phase shifters 330, and aplurality of antenna radiating elements 340, all of which are knowncomponents of a phased array antenna. Phase attenuators 320 and phaseshifters 330 are configured to control the phase of the signal deliveredto radiating elements 340. Phased array antenna 300 further comprises acontroller 350 configured to electronically control the phasing andsteering of beams radiating from and received by antenna radiatingelements 340.

Controller 350 is configured to direct the signals from antennaradiating elements 340 to a particular destination. According to oneembodiment, each antenna radiating element 340 may be configured todirect its signal towards a specific receiver. For example, an antennaradiating element may be configured to direct its signal to a specificend device or to another transmitting location.

Controller 350 may also be configured to discover broken links between aradiating element and its destination transceiver. For example, a linkmay be considered broken if it is blocked or otherwise unavailable.Controller 350 may determine that there is a problem with a link, forexample, by determining whether any messages or responses to transmittedmessage are received within a predetermined time period. According tosome embodiments, controller 350 may transmit a polling message over alink to test the operation of the link. Controller 350 may also beconfigured to perform beam steering and null steering. Controller 350may be configured to declare that a link is broken if a transmission isnot completed within a predetermined number of attempts, or if the powerlevel of return signal is below a predefined power level. Controller 350may then direct the antenna experiencing a broken link to steer its beamaround the blockage. This may include, for example, directing theantenna to another transceiver within the mesh network to complete thetransmission. As a result of the mesh configuration, the secondarytransceiver is able to communicate with the intended destination.

Null steering may be used, according to one embodiment, to increase theperformance of the mesh network when in the presence of undesiredsignal. Null steering enables the controller to direct radiatingelements to steer signals from one or more radiating antennas around anundesired signal. An undesired signal may include, for example,malicious or non-malicious sources, such as jamming signals. A jammingmay be any signal within the frequency band of the antenna radiatingelement. Thus, the controller may be configured to detect the presenceof an undesired signal and steer around it.

FIG. 4 depicts a process 400 in accordance with one embodiment of theinvention. As depicted at 410, a transceiver associated with a cableaccess point transmits data to a user device. The data may be dataoriginating at an external network or from one or more other deviceswithin the network. According to one embodiment, the transceiver locatedat the cable access point determines whether the data was successfullytransmitted, as depicted at 420. This may include, for example,determining whether an acknowledgment has been received or whether anerror message has been generated.

If the transmission is unsuccessful, the transceiver may steer itsantenna beam to an alternate location to complete the transmission, asdepicted at 430. For example, a controller associated with thetransceiver may direct the transceiver to steer to a different angle, orto use a different beam to complete the transmission via a differentreceiver.

In accordance with the various aspects of the invention described above,wireless communication is greatly improved. The system provides multiplepaths through the network, which improves communication in the event ofpath blockage, interference, or other obstructions.

The process described in connection with FIG. 4 may be implemented inhard wired devices, firmware, or software running in a processor. Aprocessing unit for a software or firmware implementation is preferablycontained in the first transceiver associated with a cable access point.This process may be contained on a computer readable medium which may beread by the first transceiver. A computer readable medium may be anymedium capable of carrying instructions to be performed by amicroprocessor, including a CD disc, DVD disc, magnetic or optical disc,tape, silicon based removable or non-removable memory, packetized ornon-packetized wireline or wireless transmission signals.

Those of skill in the art will appreciate that a computer readablemedium may carry instructions for a computer to perform a method oftransmitting data in a wireless cable mesh network comprising at leastthe steps of: transmitting a data message to a first transceiver over afirst communication link associated with a first one of a plurality ofantennas which form a phased array antenna; and determining whether thedata message is successfully received at the first transceiver, whereinif the data message is not successfully received, steering the first oneof the plurality of antennas to a second transceiver, the secondtransceiver being communicatively coupled to the first receiver in amesh configuration.

While various aspects have been described above wherein a phased arrayantenna is configured at a cable access point, one or more of the enddevices may also be equipped with a phased array antenna operating in asimilar manner. The end devices would then be able to rotate theirrespective antenna radiating elements around a broken link in order toreceive data. For example, a controller associated with the receivinglocation may direct the phased array antenna to steer to a differentangle, or use another pattern to receive signals from a differenttransmitting location while suppressing those transmissions from thenormal viewing angle.

The previous description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to these embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thespirit or scope of the invention. Thus, the present invention is notintended to be limited to the embodiments shown herein, but is to beaccorded the full scope consistent with the claims.

What is claimed is:
 1. A wireless cable network comprising: a pluralityof first transceivers associated with a cable access point andconfigured to transmit and receive data over a cable network; and aplurality of second transceivers associated with an end user device, atleast two of the plurality of second transceivers associated with an enduser device being communicatively coupled to each other in a meshconfiguration, wherein, at least one of the plurality of firsttransceivers is equipped with an electronically steerable phased arrayantenna transmitting a plurality of beams.
 2. The network of claim 1,wherein the electronically steerable phased array antenna comprises: acontroller configured to steer each beam to a desired receive location.3. The network of claim 2, wherein the controller is configured todirect one or more of the plurality of beams around an interferer. 4.The network of claim 1, wherein each of the plurality of beams isdirected to one or more predetermined second transceivers.
 5. Thenetwork of claim 2, wherein the controller is configured to determinewhether a communication link between one or more of the plurality offirst transceivers and second transceivers is unavailable.
 6. Thenetwork of claim 5, wherein the link is unavailable, the controllerdirects a signal beam associated with the unavailable link to anothertransceiver associated with another end user device in the meshconfiguration.
 7. A method of transmitting data in a wireless cable meshnetwork comprising: transmitting a data message to a first transceiverover a first communication link associated with a first one of aplurality of antennas which form a phased array antenna; and determiningwhether the data message is successfully received at the firsttransceiver, wherein if the data message is not successfully received,steering the first one of the plurality of antennas to a secondtransceiver, the second transceiver being communicatively coupled to thefirst receiver in a mesh configuration.
 8. The method of claim 7,wherein determining whether the data message is successfully receivercomprises determining whether an acknowledgement message has beenreceived.
 9. The method of claim 7, wherein the phased array antenna isan electronically steerable phased array antenna comprising a controllerconfigured to steer antenna beams to a desired receive location.
 10. Themethod of claim 7 further comprising: determining whether there is aninterferer blocking communications to the first transceiver; anddirecting one or more for the phased array antenna beams around theinterferer.
 11. A computer readable medium carrying instructions for acomputer to perform a method of transmitting data in a wireless cablemesh network, said method comprising the steps of: transmitting a datamessage to a first transceiver over a first communication linkassociated with a first one of a plurality of antennas which form aphased array antenna; and determining whether the data message issuccessfully received at the first transceiver, wherein if the datamessage is not successfully received, steering the first one of theplurality of antennas to a second transceiver, the second transceiverbeing communicatively coupled to the first receiver in a meshconfiguration.
 12. The computer readable medium according to claim 11,wherein determining whether the data message is successfully receivercomprises determining whether an acknowledgement message has beenreceived.
 13. The computer readable medium according to claim 11,wherein the phased array antenna is an electronically steerable phasedarray antenna comprising a controller configured to steer antenna beamsto a desired receive location.
 14. The computer readable mediumaccording to claim 11, wherein the method further comprises: determiningwhether there is an interferer blocking communications to the firsttransceiver; and directing one or more for the phased array antennabeams around the interferer.